774-P: Hereditary Renal Glycosuria, Diabetes, and Responses to SGLT2 Inhibitor

Aims: To present the clinical features of two rare cases with hereditary renal glycosuria and diabetes, and summarize the previously reported SLC5A2 mutations and the related phenotypes. Methods: The two patients were followed up for 7 and 3 years respectively, and detailed clinical characteristics were collected. SLC5A2 and HNF1A gene were sequenced. We used flash glucose monitoring system to record the variation of glucose with and without SGLT2 inhibitor treatment. Then we retrieved all the literature from Pubmed and analyzed SLC5A2 gene mutations and the phenotypes. Results: During regular long-time follow up, the two patients both had frequent un-proportional renal glycosuria in the morning even when their fasting serum glucose was only slightly increased above the normal range. A novel rare mutation V359G and a pathogenic rare mutation ivs7+5G>A in SLC5A2 gene were found in Case 1 and Case 2 respectively. In Case 1, the 24h glycosuria was 2.2g/d, and increased to 103g/day after dapaglifozin treatment. The average glucose (6.33±1.56 vs. 6.28±1.74mmol/L, P=0.663), and Time in Range (TIR) (95% vs. 93%) were not significantly different in metformin and dapaglifozin treatment respectively. In Case 2, the 24h glycosuria was 121.4g/d and increased to 185.8g/day after dapaglifozin add-on treatment, with a further reduction of average glucose (9.11±2.63 vs. 7.54±2.39mmol/L, P Conclusions: Genetic renal glycosuria could not be translated into protecting individuals completely from developing diabetes. The response of these patients suggested that even in diabetic patients with decreased renal glucose threshold, SGLT2 inhibitor could also be effective. Disclosure Q. Ren: None. S. Gong: None. X. Han: None. L. Ji: None. Funding National Key Research and Development Program of China (2016YFC1304901); Beijing Municipal Commission of Science and Technology (Z141100007414002, D131100005313008)